In a well perforating operation, a perforating gun string is used to carry a perforating gun downhole into a wellbore to a desired region. The perforating gun comprises a carrier tube designed to carry a plurality of charges which are detonated to form perforations that extend outwardly in a radial direction into a surrounding formation. As the carrier tube is conveyed deeper into the wellbore, a substantial pressure differential is established between the high pressure external well environment and the interior of the carrier tube. The high differential pressure increases both the collapse tendency and the leak potential of the carrier. Following perforation, the differential pressure also can drive well fluid into the perforating gun and cause a detrimental pressure pulse which propagates through the wellbore fluid.